Line tightener



FIG. 1 is a perspective view of a line tightener of my invention with the dotted line being disclosed for illustrative purposes only;

FIG. 2 is a front elevational view thereof;

FIG. 3 is an end view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof.

The rear and opposite side views are mirror images of FIGS. 2 and 3 respectively. 

The ornamental design for a line tightener, as shown and described. 